The invention is in the field of novelty items and their manufacture, particularly items such as artificial pumpkins that the consumer desires to carve or alter after purchase.
Known artificial novelty articles such as Halloween jack-o-lanterns are typically manufactured from paper products, ceramics, or thin, soft plastic and, while useful for display, are not suitable for carving by the purchaser or safe for use with lights. To honor the holiday tradition of carving pumpkins, therefore, members of the public have before now been forced to purchase real pumpkins. However, real pumpkins are perishable and therefore will rot after a time. They are messy and smelly to carve. They cannot be reused in subsequent years. There is a need, therefore, for novel application of known materials to articles that can be carved, such as artificial pumpkins that are durable, non-flammable, and carvable.
In addition, use of polyurethane foam has been limited to applications in which it can be sprayed on a planar, or nearly planar surface, such as roofing, or used in liquid form for injection molding into solid structures. However, there has before now been no known way of applying polyurethane foam to create a three-dimensional hollow structure.
It is an object of the invention, therefore, to provide new and improved novelty items that are capable of being carved.
It is another object of the invention to provide new and improved novelty items that are durable and capable of being reused.
It is another object of the invention to provide new and improved ways of applying polyurethane foam to create a three-dimensional hollow structure.
It is another object of the invention to provide new and improved artificial pumpkins.
It is another object of the invention to provide new and improved artificial Halloween jack-o-lanterns that can be used with a non-flammable light source.
The above and other objects of the invention are achieved in one disclosed embodiment through a carvable article comprising a polyurethane shell substantially surrounding an interior volume and having a thin, elastomeric coating, such as an acrylic, on the exterior surface of the shell. When formed as a novelty artificial pumpkin, the article can have features such as a stem-shaped protrusion on the top, an opening to the interior on the bottom, which may form a flat area on which the shell can be rested, and a painted, textured exterior. The shell can be shaped irregularly, as a spheroid, or as a pumpkin. In further embodiments, the coating can be textured or painted. One suitable polyurethane material has a nominal density of about 2.5-3.0 pounds per cubic foot.
The carvable article can be formed by an inventive process in which polyurethane foam material is sprayed on the inside of a rotating hollow mold with a spray nozzle, or in which the foam is sprayed from a rotating nozzle inside the mold. The nozzle may be placed at the end of a static mixing tube, in which the polyurethane foam is mixed from its components. In preferred embodiments, polyurethane foam components having slow reactive times are used, and the mold is pre-treated with a mold-release agent. After the polyurethane foam article and the mold are separated, the article is coated with an elastomeric coating, such as an acrylic material that is applied as a liquid.
Thus, the inventive articles, including those made in accordance with the inventive process, can be used as three-dimensional hollow novelty items of a variety of shapes. In addition, the inventive articles, such as Halloween pumpkins, are carvable, reusable, and can be used with a light source.
Other aspects of the invention will be appreciated by those skilled in the art after reviewing the following detailed description of the invention.